Relay.



PATENTED 001. 29. 1907.

L. F. HOWARD.

RELAY.

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PATENTBD OCT. 29. 1907. L. F. HOWARD. RELAY.

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PATENTED OCT. 29. 1907.

L. P. HOWARD.

RELAY.

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UNITED STATES PATENT OFFICE.

LEMIIEL FREDERIC HOWARD, OF EDGEWOOD PA-RK, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH AND SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPO- RATION OF PENNSYLVANIA.

No. see,4oo.

Specification of Letters Patent Application filed December 34. 1906- Ssril-l No. 349.267. Renewed September 10. 1907- Patented Oct. 29, 1907.

Serial Io. 392.210.

To all whom it may concern:

Be it known that I, Lmwicn Fasonruc Howsnn, a citizen of the United States, residing at Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Relays, of which the following is a specification.

My invention relates to relays for use in railway signaling systems and particularly to relays used in alternating current signaling systems when such systems are applied to electric railroads an alternating current for propulsion purposes and a track rail or the tracks rails in the return circuit for the propulsion current. The alternating propulsion current is generally of a low frequency, say 25 cycles, while the alternating signaling current is of a higher frequency, say cycles. As the two currents are impressed upon the track rails simultaneously during the operation of cars on the railway and the signaling system in the control of the cars traveling along the railway, and as the relays are connected with the track rails at intervals, it is obvious that provision must be made to prevent a wrong operation of the relays by the propulsion current to have a railway signal give a clear indication when a danger indication should be given. Ordinarily, the car propulsion current will flow along the track rails in its return to the power generator rather than flow through by-paths, for example, the relay coils and transformer coils, owing to the fact that the track rail or rails ofier a pathof least resistance. It sometimes happens, however, that track conditions, such as a broken rail or unequal resistances in .the two rails will produce a difference in potential of the propulsion current between the track rails at the relay terminals,

- (that is, at the points where the relay coils are connect ed with the track rails) thereby causing the power current to flow through the relay coils. Should this happen, the propulsion current will cause the relay to operate to open a circuit for the railway signal, irrespective of the position of a car relatively to the relay, and thus have the railway signal give a dangerous indication,

I will describe a relay embodying my invention and then point out the novel features thereof in claims.

In the accompanying drawings Figure 1 is a vertical sectional view of a relay embodying my invention. Fig. 2 is also a vertical sectional view but in a different plane than Fig. 1. Fig. 3 is a diagrammatical view of a portion of an electric railway, the track rails of which are divided to form block sections and are included in a return path to the generator for the car propulsion current and having applied thereto a signaling system including a relay embodying my invention.

suitably secured by bolts and carries the necemary contacts which are suitably and electrically connected with binding posts. Some of the contacts'carried by the top a are electrically connected with contacts carried upon a shaft a suitably mounted within the casing and movable in its mountings through a vane C which is acted upon by a plurality of magnetic circuits as will be hereinafter more fully explained. The arrange ment of contacts, casing and frame may conveniently be substantially like that illustrated in U. 8. Patent No. 823,086, granted June 12, 1906, to L. H. Thullen for an alternating current translating device.

A designates a laminated cor'e, substantially 0- shaped in design, which is suitably secured to the top a. The ends of the core are on opposite sides of the vane G and the ends of the core are split or bifurcated, and around one of suchv split or bifurcated por tions is placed a metallic (copper) band a.

A, A designate energizing coils, placed on the core A and in series with one another. If desired, there may be only one such coil. These coils when traversed by an alternating current, generate lines of force in the core A and these lines of force induce currents in the closed conductor band a, which current, however, is of a different phase or is out of step with the alternating current flowing in the coils A, A. The lines of force produced by these alternating currents induce eddy currents on the vane C and cause it with the shaft a and contacts carried thereby, to move in one direction, that is, to close the contacts. When the alternating current in the 'coils A, A ceases flowing for any reason, a reverse movement of the vane takes place and thus the contacts are opened. This operation of the vane is fully set forth in the patent hereinbefore referred to.

B, designates a second laminated and C-shaped core, constructed in all respects like the core A except that the closed conductor band a is placed on the opposite split or bifurcated portion. The reason of this is that when the lines of force induce the eddy currents on the vane C they will be of the opposite polarity from those generated by the core and will, therefore, produce a movement of the vane G in a direction opposite to that produced by the core A. In other words, the direction of movement of the vane 0 produced by the core B is in a direction to open the con- A, .4 If desired, there may be only one energizing -tacts, whereas the direction of movement of the vane C produced by the core A is to close the contacts. The core B, is provided with energizing coils B, B

they will not act as a short circuit for the alternating signaling current.

001'] on the com B.

t I I H designates an alternatingcurrent generator and 111 W! 185 With 0301) OM10! and In series with the coils II, It, line conductors extending therefrom. The iilternating current from the generator is of a higher frequency than the altematug propulsion current.

I I I l i i i i hi it h each hhchechn hmwha hihhhhlillil i In practice alternating curren 0 W h quency is designed to flow in all four coils, which as supplies alternating signaling current to the track cirstated are in series. Means, however, are provided cuit oi the block section from the line conductors h, h, iii shunt across one pair of coils, for example, the coils at a reduced voltage. Each track circuit as is well un- A, A, to divert a certain amount of the total current derstood, comprises a source of current (transformer T), in relay circuit from coils A, A; the amount of curthe track rails of the block section, and a relay. rent thus diverted varying inversely as the frequency. R, R, designate the relays and as hereinbefore stated These means will be in the form of an impedance they are of a type illustrated in Figs. 1 and 2. I have which may, if desired, be included within the relay only diagrammatically illustrated the relays and only casing and suitably secured in place. Means are also a coil A and a coil B. 0 provided in shunt across the other pair of coils (B, I designates an impedance across the coils A, or as B to divert a certain amount of the total current in hereinbefore stated in shunt across the coil, and I desthe relay circuit from the coils B, B the amount of ignates a capacity across the coil B. current diverted being in this case varying directly The usual operation of the signaling system is well as the frequency. These means will be in the form understood. With no car or traininablock section the of a capacity. Thus it will be seen that in consealternating signaling current will flow from one termiquence of a proper adjustment of the relations of the nal of the secondary of transformer T, along one rail, impedance and capacity, when an alternating current wires 1, 2, coil A, wires 3, 4, coil B and wires 5, 6, to of high frequency is flowing through the coils, it can the other track rail and other terminal of the secondary be made strongest in the coils A, A, and thus the of transformer T. It will be noted that the alternating vane will be caused to move to close the contacts and signaling current at the juncture of wires 1, 2, has a path when an alternating current of lower frequency is through the impedance I, but as stated the impedance flowing through the coils, it will be stronger in the chokesbackthe alternating signaling currentand causes coils B, B and the vane C will thus be caused to most of it to flow through the coil A. It will also be move in a direction to open the contacts. noted that the alternating signaling current from the Referring now to Fig. 3. This figure illustrates a recoil A at the juncture of wires 3, 4, has a path through lay involving my invention in a signaling system apthe capacity I, and as stated, the capacity is adjusted plied to an electric railway on which the cars or trains in relation to impedance 1, so that a greater part of the are propelledby an alternating current of low frequency. signaling current from the rails will flow through coil A, I have not illustrated the power generator, the feeder rather than the coil B. Thus the coil A will be the conductor extending therefrom, nor the connection of stronger and the vane will be moved to close the circuit one pole of the generator with the track rails as this is of the railway signal. When a car or train enters a well understood to those skilled in the art. Such parts block section, the wheels and axles thereof short circuit and connections, however, are to be understood as exthe alternating signaling current from the coils A, B, isting. F designates a portion of an electric railway, and they being deenergized permit a reverse moveboth track rails of which are divided at points by insument of the vane to open the circuit of the railway lation f to form block sections. I have illustrated one signal. complete block section F, and a portion of another F Should for any reason, and irrespective of the location Each block section is provided with an automatic railof a car relatively to a relay, there be such a difference way signal S at one end, the operation of which is mm of potential of the alternating propulsion current at the trolled by a relay in the usual and well known manner. terminal of the relay as would cause the propulsion cur- At the ends of each block section I provide a reactance rent to fiow through the coils A, B, such current would bond G and electrically connect the winding or windbe stronger in the coil B, for the reason before stated ings on two adjacent bonds. f 3 designates a. conductor and thus the vane 0 would be moved to open the circuit between bonds. These reactance bonds are of the balof the railway signal, and thus have the railway signal anced type, that is, the winding or windings thereof are give a dangerous indication. so arranged as to conduct the propulsion current from Of course, the number of turns in the two coils or two the two rails of a block section in reverse directions so pairs of coils may be different and the impedance and as not to produce any magnetism in the core thereof, capacity may be so proportioned as to give the best thereby leaving the bonds free to act as paths of high results. 13o impedances to the alternating signaling current. A What I claim as my invention type of such bond 15 Illustrated a Patent 1. In a relay the combination with a vane, contacts granted to L. H. Thullen. Thus it will beseen that opened and closed by movements of the vane in reverse the track rails and bonds will conduct the alternating directions, a coil and magnetic circuit for causing a ov power current back to the generator. The alternating 3:23 2 ;gi i ig ggi gf igs l g gi i z g f i current however W111 confined to the magnetic circuit for causing a movem ent of tlie vane in a lndlvldual blocks by the insulations f, and as the reverse direction when said second coil is traversed by an bOndB G across the rails, are Of such high impedance alternating current of a lower frequency, means for shuntin In liternnting current of high trequency from one coil, and means for shunting an alternating current of a lower trequency'trom the other coil.

2. In a relay the combination with n vunc, contacts opened and closed by movements 0! the vune in reverse directions, a coil and mngnetic circuit for causing a movement 0! the vane in one direction when the coil is trnverred by a high frequency alternating current, n coil and magnetic circuit for causing a movement of the vnne in a 10 reverse direction when said second coil is trnversed by in alternating current of s lower frequency, said coils being in series circuit, an impedance in shunt 'ucross the terminals of one coil and 11 capacity in shunt across the terminals of the other coil.

.In testimony whereof I have signed my name to this 15 specification in the presence of two subscribed witnesses.

LEMUEL FREDERIC HOWARD. Witnesses:

J. G. Scmucunnu, W. L. MCDANIEL. 

